Although some folks may be abusing it, it is far too less and not the main driver for longer green card queue. The reason for the longer queue is the fact that

Although some folks may be abusing it, it is far too less and not the main driver for longer green card queue. The reason for the longer queue is the fact that large number of EB-3s are jumping into EB-2 as they age their stay in US past 6 years, keeping their priority date same.